05/05/06

From Biol301

• Life History observation about frogs: will be touched on later
• Human Population
  • 30 million increase since last semester
  • Saw major growth in 4000 bc because of the advent of agriculture
  • 1800 anno domini (in the year of our Lord) saw a major growth because of industrial revolution
    • Note: Plague lasted nearly 100 years longer in Spain because they had a tradition that the soon to be widowed spouse would take the dying breath of their dying loved one.

Demography: study of factors affecting population growth and decline. Vital Statistics: age specific schedules of birth and death

• Determines age structure, growth rate / population dynamics / probability of persistance.
• Summarized in the life tables
• Assumes all individuals of the same age are alike and the entire population is female

Two (2) Types of Life Tables

1. Corhort life tables: from birth to death
2. Static life table

• For long life table\\
• Estimates of age structure and vital statistics as snapshot

Constructing Life Tables

• Tag a cohort of the age range you want to study.
• Tagged 115 individuals
• Censused population for survivors.
• Table can answer
  • What is the age specific mortality risk.
  • Highest and lowest specific mortality risk.
  • Probable lifespan
• x = age; nx = number alive at age x
• Lx = proportion of original cohort surviving to age x = probability of surviving to age x
• dx = number dying in the interval from year x to x+1
• qx = mortality rate of each age group
• Three types of survivorship curves
  • Curves are only for comparison with each other.

• Be sure to see the slides for charts and graphs for this lecture.